High Pressure pump stops after a while
 

1989 F250 XLT 5.8 efi, dual tank

After roughly 10 minutes of running, the high pressure fuel pump stops working. Turn the key off, back on, and only the low pressure in tank pump runs. I already replaced the high pressure pump, and the pigtail wire that attaches to it.

I checked continuity every which way between the inertia switch and the high pressure pump and the tank selector, both before and after it cuts out, and everything checked out okay.

Anyone ever have a similar problem, or know what is going on? According to my wiring diagram, power comes FROM the inertia switch, and splits to feed both the high pressure pump as well as the tank selector. If this is the case, it shouldnt be possible for it to be the computer, as power is fed to both the high and low pumps from the same point, unless the high pressure pump grounds through the computer. But it still has continuity, despite the high pressure pump stopping.